The invention relates to a motor vehicle. From U.S. Pat. No. 6,285,778, a detector for the motor vehicle environment is known by which a two-dimensional matrix pattern, particularly a dot matrix, is projected into an area to be observed, and the corresponding light pattern is photographed. A comparison between the photographed light pattern and a stored reference pattern, which corresponds to the light pattern on a flat road, forms the basis of the recognition of obstacles.
This solution has several disadvantages. In order to generate a two-dimensional light pattern that is used for the detection of obstacles in a certain area, it must be radiated onto the entire surface to be sensed. A relatively high luminous power is required for this purpose. Small obstacles between the dots of the light pattern may remain undetected. The assignment of the detected position of the dots to the desired positions is problematic in the case of larger obstacles. In addition, the comparison between the photographed surface-covering two-dimensional light pattern and the stored two-dimensional reference pattern for the detection of obstacles is computationally intensive. An unambiguous assignment of the individual dots in the photographed light pattern to their corresponding desired positions is not always possible. When the patterns of two adjacent vehicles with the same system overlap, the light patterns of one vehicle may overlap those of the other vehicle. No meaningful possibility is indicated to integrate the system in the motor vehicle.
It is therefore an object of the invention to provide a technical teaching for recognizing obstacles in the environment of a vehicle that can be implemented in an economical fashion.
This object is achieved in accordance with the invention. Advantageous further developments of the invention are described herein.
A motor vehicle according to the invention includes (a) an imaging device for generating an image of a radiation pattern in the environment of the motor vehicle, (b) a detecting device for the multiple, sequential detection of images of the radiation pattern influenced by the environment, and (c) a processor device which is arranged such that, based on the difference between directly or indirectly sequentially detected images of the radiation pattern, an obstacle or a turn in the road is detected in the environment.
As a result of the fact that obstacle recognition is based on a difference between successively detected images of the radiation pattern, the obstacle recognition can easily be implemented. A reference pattern that was stored beforehand during manufacturing is not absolutely necessary but may nevertheless be provided for additional purposes. The invention can thereby be put into practice in an economical fashion. As a result, the reliability of obstacle detection can also be improved.
In this case, the imaging device may include an electromagnetic radiation source, such as a laser, for in particular visible radiation or infrared radiation and/or a suitable imaging lens system, for example, a cylindrical lens, for generating a continuous line as a radiation pattern.
The radiation pattern is preferably further developed in an essentially stripe-shaped fashion, for example, as a curved line or as a boundary consisting of several segments. According to a preferred further development, the imaging device is arranged such that the image of the radiation pattern forms an essentially closed ring around the motor vehicle. As an alternative to the above, the radiation pattern surrounds the motor vehicle partially.
As a result, an image of the radiation pattern can be generated repeatedly in a reliable manner with low hardware expenditures and power expenditures. The detection of images of the radiation pattern, and of differences between images and thus of obstacles, can be reliably carried out at low computing expenditures.
It is advantageously provided that the detecting device, which detects the image of, for example, the lines in the environment of the vehicle, is synchronized with the corresponding radiation source. A power-saving pulsed operation is thereby made possible.
The detecting device may, for example, be a digital camera adapted to the wavelength of the imaging device, particularly its radiation source. There may, for example, be between 10 milliseconds and 3 seconds between directly sequential detections of the image of the radiation pattern. The in-between time may depend on the current vehicle speed, for example, such that, in each case, with a movement of the motor vehicle by 0.1 meters, the detection of an image of the radiation pattern is triggered automatically.
When the radiation pattern is recognized by the processor device, the segmentation in the sense of the image processing is preferably carried out by use of the special characteristics of the radiation pattern, such as the luminosity, the wavelength and/or the line width.
An electronic obstacle map is advantageously prepared by use of the obtained information. This electronic obstacle map can be changed to a form that can easily be interpreted by the driver of the vehicle and can be displayed, for example, on the vehicle video screen or a heads-up display. Based on the detection of an obstacle, a visual or acoustic warning signal can be emitted.
It is preferably provided that, on the basis of the curvature of the radiation pattern at the obstacles, not only their distance and the direction relative to the coordinate system of the motor vehicle are determined but, by means of a comparison of several chronologically successive detections, their relative speeds with respect to the vehicle coordinates are also computed.
The speed of the obstacles relative to the road can advantageously be computed from the relative speed of the obstacles in the coordinates of the vehicle and from the knowledge of the vehicle speed relative to the road. In this manner, a motor vehicle can differentiate between static obstacles, such as road boundaries, and the mobile obstacles, for example, a pedestrian who wants to cross the road in front of the vehicle. This differentiation is of essential significance when designing algorithms, for example, for avoiding collisions, for the protection of pedestrians, and/or for pre-crash algorithms.
The vehicle dynamics of the motor vehicle can preferably be influenced by the obtained information concerning the environment of the motor vehicle. This may be further developed as an automatic braking in front of obstacles if these are situated in the precalculated trajectory of the vehicle, and/or as an evasion with respect to recognized obstacles.
Particularly preferably, the imaging device includes an infrared laser beam device, which is further developed with a special lens system which optically transforms the laser beam such that, from its installed position in the motor vehicle, aimed at a straight road that is free of obstacles, the laser beam generates a straight or curved line. A curved cylindrical lens can, for example, be used as the optical device.
As an alternative to the above, a laser beam can be caused to carry out a rapid movement by way of a rotating mirror or, for example, by way of an optical element moved by a piezoelectric transducer, so that the one-dimensional laser beam generates a two-dimensional figure in the environment of a motor vehicle.
The imaging device is preferably set up such that, when it is assumed that an environment does not change relative to the motor vehicle, the image of the radiation pattern rests in the coordinate system of the vehicle or is moved along with the motor vehicle. In contrast to the known LIDAR technology, no precise controlled deflection of the beam in two directions is therefore required for the obstacle recognition. The radiation pattern moves together with the vehicle. The points-in-time for the detection of the current image of the radiation pattern can be automatically computed from the movement of the vehicle, which is detected, for example, by way of wheel sensors. As a result, it is also not absolutely necessary to expose the vehicle environment in a surface-covering manner to a dot matrix radiation and to sense it. The required information concerning the position, the size and, if required, the inherent speed of the motor vehicle can be obtained by means of the inherent speed of the vehicle or a rotation of the door during the opening as soon as these are impacted by the radiation pattern.
The recognition of an obstacle is preferably based on the comparison of the displacement of the image of the radiation pattern and the displacement of other textures and/or edges in the image of the environment detected by the detecting device. It is preferably provided that the presence of obstacles can be assumed if a clearly deviating displacement or curvature of the image of the radiation pattern relative to the edges extracted from the detected image of the environment takes place at certain points of the detected image.
The imaging device and the detecting devices are preferably arranged at a distance from one another. Only in this case can the change of the shape of the image of the radiation pattern be detected due to obstacles. In particular, the imaging device and the detecting device are arranged above one another and, in the vertical direction, are arranged at a mutual distance of, for example, 10 cm.
Preferably in the case of a locked vehicle, a threat of theft or vandalism can be assumed based on the difference between indirectly or directly sequentially (chronologically successively) detected images of the radiation pattern, and a corresponding warning signal is generated, which can be emitted, for example, visually and/or acoustically directly at the motor vehicle or is emitted after a message transmission from the vehicle to a remote unit, for example by way of a mobile radio system at the remote unit.
As a result of a relatively low power consumption of the device in comparison to the systems that require a clearly stronger illumination of the environment, the system can operate particularly in a pulsed operation as a replacement or support of an antitheft warning system.
By means of the detected change of the image of the radiation pattern, such as a line, from one pulse timing to the next, preferably not only the violation of a safety zone is determined but an object classification is also carried out. For example, the approach of a pedestrian can be automatically differentiated from the approach of another motor vehicle because these approaches result in different curvatures of the safety ring. Such a further development has an advantage in comparison to a conventional antitheft warning system which cannot carry out a classification of the objects.
A preferred further development provides that a radiation pattern assigned to the motor vehicle or originating from the motor vehicle or the pertaining imaging device is recognized or can be separated from the radiation pattern of another vehicle in that the detected image corresponds to the generated image with respect to its shape, particularly with respect to its curvature (convex or concave).
A clear differentiability of the image of the radiation pattern of the own vehicle from the perspective of its detecting device from the image of the radiation pattern of another vehicle with the same system offers a significant advantage with respect to the known state of the art.
Advantageously, the imaging device, particularly for the sections of the environment situated laterally with respect to the vehicle, can be cost-effectively and functionally built into a door handle, for example, together with the front end area lighting unit of the vehicle. The detecting device, particularly for the sections of the environment situated laterally with respect to the vehicle, can preferably be built into a lateral mirror of the motor vehicle. For the detection and further processing of the image of the radiation pattern, an existing top view camera system can be used or can be built in together with the latter. The top view camera preferably is a system for displaying to the driver a geometrically transformed camera image of sections of the environment situated laterally with respect to the vehicle. The imaging device for the forward area of the vehicle is preferably cost-effectively and functionally built into a decorative element, for example, a manufacturer's emblem. In this case, the radiation pattern can be deflected, for example, by way of a mirror and/or prism which, in particular, can be hinged.
The deflection of the radiation pattern in a mirror is very advantageous, particularly with respect to better meeting the safety standard for the use of the laser technique in the motor vehicle. As a result, the exit lens system of the laser can be built into the interior of the vehicle in a manner not accessible from the outside. It is therefore not possible to look directly into the exit lens system which, in the case of a relatively high emitted power, could result in possible damage to the retina. The radiation reflected in a deflecting mirror, which according to the invention is emitted, for example, as a line into the environment of the vehicle, is even largely harmless when looking directly into the mirror because, at a certain distance from the lens system, the radiant power is already relatively widely fanned out and can generate a much lower luminous power per unit of surface, for example, on the retina.
Advantageously, a further development of a forward-directed camera system of the vehicle, such as a lane departure warning system, can be used in a cost-effective and functional manner as the detecting device for an area situated in front of the vehicle. The detecting device is preferably constructed in a cost-effective and functional manner as a further development of a backup camera for areas situated behind the vehicle. Since the above-mentioned camera systems already have high-power image processing units, the invention or its further developments can be implemented at low expenditures.
Particularly when the imaging device and/or the detecting device is integrated in a side mirror of the motor vehicle, it is preferably provided that, based on the difference between sequentially detected images of the radiation pattern, an obstacle is detected which hinders the opening of a vehicle door.
Particularly preferably, it is provided that the time between the sequential generation of images of the radiation pattern and/or the successive detections of images of the radiation pattern influenced by the environment depends on the vehicle movement, for example, such that repeatedly, after a movement of the vehicle by a predefined distance of, for example, 10 to 50 centimeters, a generating of an image and/or a detecting of an image is triggered. The measuring of the predefined distance can be carried out, for example, by use of wheel sensors present in the vehicle. Additionally, the distance between two neighboring detections of the environment can be made dependent on the current speed range of the vehicle. As a result, parking and maneuvering with high demands on the precision of the obstacle detection and a detection of the environment, for example, for pre-crash applications for the higher speed range, can be supported by higher demands on the real-time cap ability.
Preferably, based on sequentially detected images of the radiation pattern, the time between the sequential detection of the images and the vehicle speed, information concerning the vehicle environment, particularly concerning the presence, the size, the shape and the relative speed of the obstacles in the environment of the vehicle, is obtained, which can be further processed as the basis of the triggering of automatic warning functions and/or the intervention in the dynamics of a vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.